000
FXUS61 KBTV 292317
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
717 PM EDT Mon Jun 29 2020

.SYNOPSIS...
Showers and embedded thunderstorms will continue through the
middle of the week bringing some much needed rain to the area.
Expect precipitation amounts between a quarter and half an inch
with locally higher amounts in thunderstorms. High temperatures
will generally be in the mid 70s to around 80 with moderate
humidity levels. Drier conditions are expected Thursday heading
into the weekend.

&&

.NEAR TERM /THROUGH TUESDAY NIGHT/...
As of 716 PM EDT Monday...Going forecast is in great shape with
little change in weather through the evening. Showers have been
most widespread across far northern Vermont, which is in the
path of moisture wrapping around the upper level low over the
Gulf of Maine. In general have boosted cloud cover for the
overnight expecting clouds to fully obscure our skies. IR
satellite imagery reveals a deep and broad plume of water vapor
targeting our forecast area. Also refreshed temperatures and
dewpoints based on recent observations and removed chances of
thunder for the remainder of the evening as no lightning has
been observed for the past couple of hours with the showers and
low-level stability will only increase as we approach sunset.
Otherwise, no other changes needed at this time.

Previous Discussion...
Fairly widespread precipitation will persist this evening and
through the early overnight hours as upper level trough and
maritime moisture continue to pivot overhead. A few embedded
rumbles of thunder are possible this evening, but better
convective chances are beginning to wane as thickening cloud
cover and lack of instability will inhibit any appreciable
vertical development of storms. Still nonetheless, additional
beneficial rainfall amounts between 0.10- .40" are expected
through early Tuesday morning. Given ample low level moisture,
fog and low clouds will once again be likely overnight which
will keep nighttime lows from really dropping. Temperatures will
be in the low 60s for the broader valleys with upper 50s across
the mountains.

A similar, wash, rinse and repeat pattern will be on tap for
tomorrow as center of low pressure remains nearly stationary just
off the MA coastline. A few subtle differences will make for a
slightly better convective threat as upper level low becomes
displaced to the SE as high pressure over southern Quebec tries to
move south. Model progs show airmass just to our west near the
eastern shores of Lake Ontario will gradually shift eastward. This
should allow for better daytime instability with periods of clearing
during the morning/early afternoon hours. Forecast high temperatures
will be about 5 or so degrees warmer than today in the mid 70s to
around 80 for valleys and low/mid 70s across the mountains. While
better bulk shear continues to remain off to our NW, greater
available instability will allow for better vertical development of
storms than we saw today. Still not looking at any severe threat,
but a few stronger storms could produce gusty winds and heavy
rainfall.

&&

.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
As of 344 PM EDT Monday...A vort max within the upper low will pivot
into the North Country during the day on Wednesday. With the cool
temperatures aloft, CAPE values should rise towards 500-1000 J/kg.
BUFKIT soundings show tall, skinny CAPE profiles and a warm mid-
level layer keeping low- level lapse rates from becoming anything
noteworthy. Additionally, only marginal shear will be available with
the better shear parameters holding off until the overnight hours.
With forcing from vorticity advection, there should be scattered to
numerous garden variety thunderstorms, especially east of the
Greens. Temperatures will be warmest west, where partial clearing
should allow temps to warm into the mid 80s, but area east of the
Greens will likely remain in the 70s. Plentiful cloud cover and
moisture will keep overnight lows in the upper 50s to mid 60s.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
As of 344 PM EDT Monday...Upper low finally opens up and departs
eastward. This will allow a ridge to build in its place and hot air
that has been trapped in Canada to filter into our region. 925hPa
temps climb upward to 23-24 C, which will translate to surface
temperatures around 90 in the valleys. Weak height rises and
continued mid-level warming will make for poor lapse rates once
again. It may take awhile for convection to develop, but an
approaching backdoor cold front will provide later in the evening.
Similar to Wednesday, it appears the better shear will arrive late
in the day past peak diurnal instability.

Beyond the passage of the backdoor cold front, model consensus is
not great with regard to mass fields. However, all favor above
normal temperatures under northwest flow periodically allowing weak
perturbations to round the upper high to our west. Daily high temps
and dewpoints are high enough that an isolated shower or
thunderstorm will be possible each day.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
Through 18Z Tuesday...Variable aviation conditions continue
over the next 24 hrs with mix of VFR/MVFR/IFR as upper level
trough remains overhead. This afternoon, ceilings have mostly
lifted to VFR/MVFR but local IFR is being reported in the
heaviest of showers/thunderstorms. Expect highly changeable
categories across the airspace as precipitation continues to
pivot across the region this afternoon. Overnight, anticipate
low ceilings/fog to return with MVFR/IFR conditions likely,
lowest at KMPV & KSLK. Tomorrow, anticipate similar aviation
forecast with return of diurnally driven showers/thunderstorms
and locally lower aviation conditions. Winds this afternoon will
be largely out of the north/northeast around 5-15 kt,
diminishing overnight to around 5 kt or less before increasing
again tomorrow afternoon around 5 to 15 kt.

Outlook...

Tuesday Night: Mainly VFR, with local IFR possible. Chance SHRA,
Slight chance TSRA.
Wednesday: Mainly VFR, with local IFR possible. Chance SHRA,
Slight chance TSRA.
Wednesday Night: VFR. Chance SHRA, Slight chance TSRA.
Thursday: VFR. Slight chance SHRA, Slight chance TSRA.
Thursday Night: VFR. NO SIG WX.
Friday: Mainly VFR, with local MVFR possible. Chance SHRA.
Friday Night: Mainly VFR, with areas MVFR possible. Slight chance
SHRA.
Independence Day: Mainly VFR, with local MVFR possible. Slight
chance SHRA.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.

&&

$$
SYNOPSIS...LaRocca
NEAR TERM...Kutikoff/LaRocca
SHORT TERM...Haynes
LONG TERM...Haynes
AVIATION...LaRocca